Learning Objectives:

Upon completion of this experiment, students will:

1. 1. 1. (CLO1). Explain basic chemical concepts related to chemical changes, energy, and properties of matter.  

      2. Identify Double Replacement and Redox Reactions

      3. Apply solubility rules of ionic compounds toward determining whether a reaction will produce a precipitate.

      4. Write net ionic equations and predict products for precipitation and acid/base reactions.

      5. Apply oxidation number rules toward determining the oxidation number of each element in a compound or polyatomic ion.

      6. Identify the various components of an oxidation-reduction reaction including reducing/oxidizing agents and half-reactions to be able to balance the redox reaction.

      7. Use observations to prove the order of elements in the activity series

A precipitate is the formation of an insoluble solid when two solutions are mixed.  Solubility is very important in understanding whether the reaction will occur. Some substances are soluble in water and others are not.  The solubility of ionic compounds can be predicted by the ions present.  Look up solubility rules in the Appendix of the Lab Manual. 

When two separate aqueous ionic compounds are mixed the ions may interact.  The ionic compounds in a double replacement reaction switches partners.  If these partners result in a compound that remains dissolved, then the products of the mixture are strong electrolytes and the reaction is said to have no apparent reaction.  When the product of the double replacement reaction is a precipitate or solid, a weak electrolyte or acid, a non electrolyte or a gaseous substance, the removal of the freely dissociated ions results in the removal of ions from solution and a chemical change has occurred. 

The driving forces that cause a reaction to occur are

• • • the formation of a solid or precipitate which results from the formation of a substance that has limited or no solubility.

      • The solubility rules are used to predict which substances will be more likely to form a precipitate.

    • the formation of a gas which is most commonly seen when the reaction results in the formation of two common weak acids:  carbonic acid: H2CO3 which dissociates to make water and CO2 gas and sulfurous acid, H2SO3, which dissociated to make water and SO2 gas; and

    • the formation of a weak or non electrolyte, such as water, which is generally recognized by the evolution of heat or

    • a significant change in temperature.

Oxidation Reduction Reactions 

Redox (reduction-oxidation) reactions include all chemical reactions in which atoms have their oxidation state changed. This can be either a simple redox process, such as the oxidation of carbon to yield carbon dioxide (CO2) or the reduction of carbon by hydrogen to yield methane (CH4), or a complex process such as the oxidation of glucose (C6H12O6) in the human body through a series of complex electron transfer processes.

Fundamentally, redox reactions are a family of reactions that are concerned with the transfer of electrons between species.

The term comes from the two concepts of reduction and oxidation. It can be explained in simple terms:

• • Oxidation is the loss of electrons or an increase in oxidation state by a molecule, atom, or ion. 

  • Reduction is the gain of electrons or a decrease in oxidation state by a molecule, atom, or ion. 

Oxidation Reduction reactions (Redox) involve the movement of electrons from one species to another species.  In learning to balance these chemical reactions, the number of atoms and the number of electrons must be balanced in the chemical reaction.  One method of balancing redox reactions involves the use of oxidation and reduction half reactions.  A half reaction is the representation of a single movement of electrons to the species who has either lost electrons (oxidation) or the species who has gained electrons (reduction). 

These reactions often involve many spectator ions including H+, OH1- and H2O.  Ionic compounds can be written without the complementary ions such as Mn2+ without the anion Cl1- ions to balance the charge or MnO41- without a Na+ or K+ ion.  

Pre Writing assignment

There is no required pre laboratory writing assignment. 

Pre laboratory Problems

The pre laboratory problems are questions about the laboratory assignment, background, definitions or procedure and calculations. These problems should be completed BEFORE coming to the class where the assignment will be discussed.

Creating properly formatted chemistry documents can be a challenge due to the superscripts and subscripts that are required to  write a formula or ion properly.   Most document programs such as Google docs or Microsoft Word can format the type in different fonts, sizes and colors.  But they can also change the position and create superscripts  or subscripts.  In this document, I would like you to properly format the compounds and ions with superscripts and subscripts.  There are a few methods to do this but you can use key strokes to easily produce the formatted superscripts and subscripts.   

In Google documents, to format a superscript, click on the control key and the period key at the same time to turn on, type the number or letter you want to be a superscript, and then click both again to turn off.  Subscripts are the control key and the comma key.    

In Microsoft Word documents, hold the control key, the shift key and the plus or equal key to turn subscripts on and off, use the control key with the plus or equal key to turn subscripts on and off. 

Part A - Net Ionic Reactions for Double Replacement Reactions

Part B - Net Reactions of Oxidation Reduction Reactions

Part C -Reactivity of Metals

Post Laboratory Problems and Conclusion paragraph

There are no post laboratory problems or conclusion paragraph for this laboratory assignment.